title: PAS-induced potentiation of cortical-evoked activity in the dorsolateral prefrontal cortex.
abstract: Neuroplasticity and long-term potentiation (LTP) in the dorsolateral prefrontal cortex (DLPFC) are considered important mechanisms in learning and memory, and their disruption may be related to the pathophysiology of several neuropsychiatric disorders. Paired associative stimulation (PAS) is a brain stimulation paradigm that produces enhanced activity in the human motor cortex that may be related to LTP. In a group of 15 healthy participants, we report on the potentiation of cortical-evoked activity in the human DLPFC using the combination of PAS and electroencephalography. In contrast, a PAS control condition did not result in potentiation in another group of nine healthy participants. We also demonstrate that PAS-induced potentiation of cortical-evoked activity is characterized by anatomical specificity that is largely confined to the site of stimulation. Finally, we show that PAS results in potentiation of θ- and γ-activity and θ-phase-γ-amplitude coupling. These neurophysiological indices may be related to working memory, an important function of the DLPFC. To our knowledge, this is the first report of potentiation of cortical-evoked activity in the DLPFC. As this potentiation may be related to LTP, our findings provide a model through which neuroplasticity in health and disease states in the frontal cortex can be studied.
authors.affiliation: 1] Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada [2] Temerty Centre for Therapeutic Brain Intervention at the Centre for Addiction and Mental Health, Toronto, ON, Canada.
authors.forename: Tarek K
authors.initials: TK
authors.lastname: Rajji
authors.forename: Yinming
authors.initials: Y
authors.lastname: Sun
authors.forename: Reza
authors.initials: R
authors.lastname: Zomorrodi-Moghaddam
authors.forename: Faranak
authors.initials: F
authors.lastname: Farzan
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Blumberger
authors.forename: Benoit H
authors.initials: BH
authors.lastname: Mulsant
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fitzgerald
authors.forename: Zafiris J
authors.initials: ZJ
authors.lastname: Daskalakis
mesh_terms: D000293:Adolescent; D000328:Adult; D058256:Brain Waves / Q000502:physiology*; D004569:Electroencephalography; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D017397:Prefrontal Cortex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult